This application pertains to the art of surgical instruments and specialized procedures using those instruments. More particularly, the application pertains to methods and apparatus for more easily and precisely using laser energy to perform surgical procedures such as arthroscopic meniscectomies and OB/GYN surgery including cervical procedures.
The invention is particularly adapted for use with laser-powered surgical tools and will be described with particular reference thereto, although it will be appreciated that the invention has broader application such as for use with other surgical tissue removal tools, including elongate fixed or rotatable blade knives or the like.
Meniscectomy tools have heretofore comprised simple surgical steel meniscectomy knives as taught in U.S. Pat. No. 4,289,132 and laser "knives" which use a laser light beam for ablating tissue to a selectable depth or beam penetration as taught in U.S. Pat. No. 5,037,421. An improvement over the fixed meniscectomy knife that has met with some acceptance in the surgical community comprises a rotatable tandem edged blade enclosed in an elongated sheath as taught in U.S. Pat. No. 4,834,729. The sheath is suitably provided with one or more circumferential openings on a distal end. By manipulating the knife, the tissue to be removed is received through the openings and encounters the rotating blades.
The surgical steel knives (non-laser) described above provide the surgeons with a certain "feel" by which continuous manual tactile feedback of the cutting edge position against the tissue is used to determine the correctness of the cut for proper tissue removal. Some surgeons find this tactile feedback highly desirable for certain procedures. However, laser knives in general do not provide much feedback. Thus, the laser knife is not used as frequently as one would expect.
One desirable feature of the laser knife not found in conventional knives, however, is the ability of the laser to precisely ablate tissue by heat vaporization. There is thus no need to subsequently withdraw or otherwise remove the severed tissue from the area. In addition, the depth of the "cut" is controllable by regulating the intensity and pulse width of the laser light beam itself. However, the laser knife does not provide the amount of tactile feedback as is obtainable using the traditional meniscectomy knives as described above. Also, the laser knives currently available do not conveniently permit the surgeon to see the depth of the cut. Because of these problems, many benefits of the laser instruments are missed by surgeons confident only in the use of traditional tools.
The present invention contemplates new and improved methods and apparatus which combine the benefits of traditional meniscectomy-type knives with the benefits of newly developed laser tissue ablating knives. The invention overcomes the above noted problems and provides an easy and inexpensive vehicle for obtaining tactile laser tip position feedback in a laser knife.